**Core Concept**
Tinea Capitis, also known as ringworm of the scalp, is a fungal infection caused by dermatophytes that invade the hair shaft and surrounding skin. The condition is characterized by circular patches of hair loss, scaling, and inflammation of the scalp.

**Why the Correct Answer is Right**
The correct answer is **Trichophyton rubrum**, a dermatophyte that typically causes tinea pedis (athlete's foot), tinea unguium (fungal nail infection), and tinea corporis (body ringworm). While Trichophyton rubrum can infect various parts of the body, it is not a common cause of Tinea Capitis. In contrast, other dermatophytes like Trichophyton tonsurans, Microsporum canis, and Epidermophyton floccosum are more commonly associated with Tinea Capitis.

**Why Each Wrong Option is Incorrect**
* **Option A:** Trichophyton tonsurans is a common cause of Tinea Capitis, particularly in the United States and other tropical regions. It is known to infect the hair shaft and surrounding skin, leading to characteristic circular patches of hair loss.
* **Option B:** Microsporum canis is a common cause of Tinea Capitis in children, especially in regions where cats and dogs are common pets. It is known to infect the hair shaft and surrounding skin, leading to circular patches of hair loss and inflammation.
* **Option C:** Epidermophyton floccosum is a dermatophyte that typically causes tinea pedis (athlete's foot) and tinea cruris (jock itch). However, it can also cause Tinea Capitis, particularly in adults.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that different dermatophytes can cause Tinea Capitis, and the causative agent can vary depending on the region and population. A high index of suspicion and a thorough examination are crucial for diagnosing and treating Tinea Capitis.

**Correct Answer:** D. Trichophyton rubrum